A major goal of this project is to establish an animal model of bitemporal human amnesia. The development of an experimental animal model for the study of a clinical disease entity in humans has always been one of the goals of neuroscience research. We are proposing a program of study in monkeys involving the bitemporal brain regions that have been implicated in human amnesia, and in normal human memory processes. This research program should help identify which specific brain structures are involved in human amnesia and clarify how they are involved. Specifically, the work is designed to 1) clarify further the effects on memory of separate or combined bilateral damage to the hippocampus and the amygdala in monkeys, when memory is tested with four tasks similar to those sensitive to human amnesia; 2) determine the effects of distraction on the performance of two delay-type tasks in normal and operated monkeys; 3) determine whether a newly formulated distinction, between that kind of learning which is spared in human amnesia and that which is not, can be demonstrated in monkeys with temporal lobe lesions. Performance will be compared on pattern discrimination learning and delayed retention of object discriminations; 4) determine if the effects of bitemporal lesions extend to both recognition memory (the ability to remember which of two objects is equally familiar) and association memory (the ability to remember which of two equally familiar objects was associated with reward). Equivalent tests of recognition and association memory will be given to all groups. 5) Determine if the behavioral effects of bitemporal lesions extend beyond the visual modality by administering analagous tests in the auditory mode; 6) determine if there is a discontinuity between premorbid and postmorbid memory in monkeys with bitemporal damage by operating on the normal group who have previously learned the tasks and retesting them.